conditional optional unwrapping

compiler_tests.odin

@@ -3710,3 +3710,198 @@ deeply_nested_child_packages_load_recursively :: proc(t: ^testing.T) {
 	state := run_executable(output)
 	testing.expect_value(t, state.exit_code, 9)
 }
+
+@(test)
+function_returning_only_in_if_branch_is_diagnosed :: proc(t: ^testing.T) {
+	text := `classify :: func(n i32) i32 {
+	if n > 0 {
+		return 1
+	}
+}
+main :: func() void {
+	_ = classify(5)
+}
+`
+	source_file := source.Source{path="test.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	found := false
+	for diagnostic in diagnostics.items {
+		found = found || strings.contains(diagnostic.message, "does not return a value")
+	}
+	testing.expect(t, found)
+}
+
+@(test)
+function_returning_in_both_if_arms_is_accepted :: proc(t: ^testing.T) {
+	text := `classify :: func(n i32) i32 {
+	if n > 0 {
+		return 1
+	} else {
+		return 0
+	}
+}
+main :: func() void {
+	_ = classify(5)
+}
+`
+	source_file := source.Source{path="test.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	found := false
+	for diagnostic in diagnostics.items {
+		found = found || strings.contains(diagnostic.message, "does not return a value")
+	}
+	testing.expect(t, !found)
+}
+
+@(test)
+function_returning_after_if_is_accepted :: proc(t: ^testing.T) {
+	text := `classify :: func(n i32) i32 {
+	if n > 0 {
+		return 1
+	}
+	return 0
+}
+main :: func() void {
+	_ = classify(5)
+}
+`
+	source_file := source.Source{path="test.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	found := false
+	for diagnostic in diagnostics.items {
+		found = found || strings.contains(diagnostic.message, "does not return a value")
+	}
+	testing.expect(t, !found)
+}
+
+@(test)
+conditional_unwrap_compiles_and_runs :: proc(t: ^testing.T) {
+	output := "/tmp/brolang-test-conditional-unwrap"
+	defer _ = os.remove(output)
+	status := compiler_core.compile_package("examples/programs/conditional_unwrap", output)
+	testing.expect_value(t, status, 0)
+	state := run_executable(output)
+	// present scalar binds and unwraps (40), none takes the else (+2), a present
+	// optional pointer binds and derefs (+0), a none optional pointer is skipped.
+	testing.expect_value(t, state.exit_code, 42)
+}
+
+@(test)
+if_unwrap_on_non_optional_is_diagnosed :: proc(t: ^testing.T) {
+	text := `main :: func() i32 {
+	x i32 = 5
+	if x |v| {
+		return v
+	}
+	return 0
+}
+`
+	source_file := source.Source{path="test.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	found := false
+	for diagnostic in diagnostics.items {
+		found = found || strings.contains(diagnostic.message, "unwrap requires an optional")
+	}
+	testing.expect(t, found)
+}
+
+@(test)
+if_unwrap_binding_is_scoped_to_then_block :: proc(t: ^testing.T) {
+	// The binding `v` is usable in the then-block but not in the else-block.
+	text := `main :: func() i32 {
+	a ?i32 = 1
+	if a |v| {
+		return v
+	} else {
+		return v
+	}
+}
+`
+	source_file := source.Source{path="test.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	found := false
+	for diagnostic in diagnostics.items {
+		found = found || strings.contains(diagnostic.message, "unresolved global 'v'")
+	}
+	testing.expect(t, found)
+}
+
+@(test)
+if_unwrap_binding_is_immutable :: proc(t: ^testing.T) {
+	text := `main :: func() i32 {
+	a ?i32 = 1
+	if a |v| {
+		v = 2
+		return v
+	}
+	return 0
+}
+`
+	source_file := source.Source{path="test.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	found := false
+	for diagnostic in diagnostics.items {
+		found = found || strings.contains(diagnostic.message, "cannot assign immutable local 'v'")
+	}
+	testing.expect(t, found)
+}